X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/5fa8d6780a107eb5ae1ff8a233b0dd23cb065f8a..65b0ef3e4abf59f79ff89fa7644aff2451922729:/examples/msg/bittorrent/peer.c diff --git a/examples/msg/bittorrent/peer.c b/examples/msg/bittorrent/peer.c index baa8bc1672..88b287f69b 100644 --- a/examples/msg/bittorrent/peer.c +++ b/examples/msg/bittorrent/peer.c @@ -1,5 +1,5 @@ - /* Copyright (c) 2012. The SimGrid Team. - * All rights reserved. */ +/* Copyright (c) 2012. The SimGrid Team. + * All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it * under the terms of the license (GNU LGPL) which comes with this package. */ @@ -9,23 +9,36 @@ #include "messages.h" #include #include +#include XBT_LOG_NEW_DEFAULT_CATEGORY(msg_peers, "Messages specific for the peers"); //TODO: Let users change this /* * File transfered data - * + * For the test, default values are : * File size: 10 pieces * 5 blocks/piece * 16384 bytes/block = 819200 bytes */ -static int FILE_SIZE = 10 * 5 * 16384; -static int FILE_PIECES = 10; -static int PIECES_BLOCKS = 5; -static int BLOCK_SIZE = 16384; -static int BLOCKS_REQUESTED = 2; +#define FILE_PIECES 10 +#define PIECES_BLOCKS 5 +#define BLOCK_SIZE 16384 /** + * Number of blocks asked by each request + */ +#define BLOCKS_REQUESTED 2 + + +static const int FILE_SIZE = FILE_PIECES * PIECES_BLOCKS * BLOCK_SIZE; + +void request_new_piece_to_peer(peer_t peer, connection_t remote_peer); +void send_request_to_peer(peer_t peer, connection_t remote_peer, int piece); +void remove_current_piece(peer_t peer, connection_t remote_peer, + int current_piece); + + + /** * Peer main function */ int peer(int argc, char *argv[]) @@ -48,12 +61,14 @@ int peer(int argc, char *argv[]) XBT_DEBUG("Got %d peers from the tracker", xbt_dict_length(peer.peers)); XBT_DEBUG("Here is my current status: %s", peer.bitfield); peer.begin_receive_time = MSG_get_clock(); + MSG_mailbox_set_async(peer.mailbox); if (has_finished(peer.bitfield)) { peer.pieces = FILE_PIECES; send_handshake_all(&peer); seed_loop(&peer, deadline); } else { leech_loop(&peer, deadline); +// XBT_INFO("%d becomes a seeder", peer.id); seed_loop(&peer, deadline); } } else { @@ -84,14 +99,17 @@ void leech_loop(peer_t peer, double deadline) */ send_handshake_all(peer); //Wait for at least one "bitfield" message. - wait_for_pieces(peer, deadline); +// wait_for_pieces(peer, deadline); XBT_DEBUG("Starting main leech loop"); + while (MSG_get_clock() < deadline && peer->pieces < FILE_PIECES) { if (peer->comm_received == NULL) { +// XBT_INFO("irecv"); peer->task_received = NULL; peer->comm_received = MSG_task_irecv(&peer->task_received, peer->mailbox); } if (MSG_comm_test(peer->comm_received)) { +// XBT_INFO("comm_test OK"); msg_error_t status = MSG_comm_get_status(peer->comm_received); MSG_comm_destroy(peer->comm_received); peer->comm_received = NULL; @@ -99,14 +117,7 @@ void leech_loop(peer_t peer, double deadline) handle_message(peer, peer->task_received); } } else { - if (peer->current_piece != -1) { - send_interested_to_peers(peer); - } else { - //If the current interested pieces is < MAX - if (peer->pieces_requested < MAX_PIECES) { - update_current_piece(peer); - } - } + handle_pending_sends(peer); //We don't execute the choke algorithm if we don't already have a piece if (MSG_get_clock() >= next_choked_update && peer->pieces > 0) { update_choked_peers(peer); @@ -170,9 +181,8 @@ int get_peers_data(peer_t peer) msg_comm_t comm_received; while (!send_success && MSG_get_clock() < timeout) { XBT_DEBUG("Sending a peer request to the tracker."); - msg_error_t status = - MSG_task_send_with_timeout(task_send, TRACKER_MAILBOX, - GET_PEERS_TIMEOUT); + msg_error_t status = MSG_task_send_with_timeout(task_send, TRACKER_MAILBOX, + GET_PEERS_TIMEOUT); if (status == MSG_OK) { send_success = 1; } @@ -233,15 +243,15 @@ void peer_init(peer_t peer, int id, int seed) peer->pieces = 0; peer->pieces_count = xbt_new0(short, FILE_PIECES); - peer->pieces_requested = 0; peer->current_pieces = xbt_dynar_new(sizeof(int), NULL); - peer->current_piece = -1; peer->stream = RngStream_CreateStream(""); peer->comm_received = NULL; peer->round = 0; + + peer->pending_sends = xbt_dynar_new(sizeof(msg_comm_t), NULL); } /** @@ -258,6 +268,7 @@ void peer_free(peer_t peer) xbt_dict_free(&peer->peers); xbt_dict_free(&peer->active_peers); xbt_dynar_free(&peer->current_pieces); + xbt_dynar_free(&peer->pending_sends); xbt_free(peer->pieces_count); xbt_free(peer->bitfield); xbt_free(peer->bitfield_blocks); @@ -274,6 +285,66 @@ int has_finished(char *bitfield) return ((memchr(bitfield, '0', sizeof(char) * FILE_PIECES) == NULL) ? 1 : 0); } +int nb_interested_peers(peer_t peer) +{ + xbt_dict_cursor_t cursor = NULL; + char *key; + connection_t connection; + int nb = 0; + xbt_dict_foreach(peer->peers, cursor, key, connection) { + if (connection->interested) + nb++; + } + return nb; +} + +/** + * Handle pending sends and remove those which are done + * @param peer Peer data + */ +void handle_pending_sends(peer_t peer) +{ + int index; + + while ((index = MSG_comm_testany(peer->pending_sends)) != -1) { + msg_comm_t comm_send = + xbt_dynar_get_as(peer->pending_sends, index, msg_comm_t); + int status = MSG_comm_get_status(comm_send); + xbt_dynar_remove_at(peer->pending_sends, index, &comm_send); + XBT_DEBUG + ("Communication %p is finished with status %d, dynar size is now %lu", + comm_send, status, xbt_dynar_length(peer->pending_sends)); + + msg_task_t task = MSG_comm_get_task(comm_send); + MSG_comm_destroy(comm_send); + + if (status != MSG_OK) { + task_message_free(task); + } + } +} + +void update_active_peers_set(peer_t peer, connection_t remote_peer) +{ + + if (remote_peer->interested && !remote_peer->choked_upload) { + //add in the active peers set + xbt_dict_set_ext(peer->active_peers, (char *) &remote_peer->id, + sizeof(int), remote_peer, NULL); + } else { + //remove + xbt_ex_t e; + TRY { + xbt_dict_remove_ext(peer->active_peers, (char *) &remote_peer->id, + sizeof(int)); + } + CATCH(e) { + xbt_ex_free(e); + } + } +} + + /** * Handle a received message sent by another peer * @param peer Peer data @@ -307,9 +378,11 @@ void handle_message(peer_t peer, msg_task_t task) update_pieces_count_from_bitfield(peer, message->bitfield); //Store the bitfield remote_peer->bitfield = xbt_strdup(message->bitfield); - //Update the current piece - if (peer->current_piece == -1 && peer->pieces < FILE_PIECES) { - update_current_piece(peer); + xbt_assert(!remote_peer->am_interested, + "Should not be interested at first"); + if (is_interested(peer, remote_peer)) { + remote_peer->am_interested = 1; + send_interested(peer, message->mailbox); } break; case MESSAGE_INTERESTED: @@ -319,13 +392,15 @@ void handle_message(peer_t peer, msg_task_t task) "A non-in-our-list peer has sent us a message. WTH ?"); //Update the interested state of the peer. remote_peer->interested = 1; + update_active_peers_set(peer, remote_peer); break; case MESSAGE_NOTINTERESTED: - XBT_DEBUG("Received a NOTINTERESTED message from %s (%s)", message->mailbox, - message->issuer_host_name); + XBT_DEBUG("Received a NOTINTERESTED message from %s (%s)", + message->mailbox, message->issuer_host_name); xbt_assert((remote_peer != NULL), "A non-in-our-list peer has sent us a message. WTH ?"); remote_peer->interested = 0; + update_active_peers_set(peer, remote_peer); break; case MESSAGE_UNCHOKE: xbt_assert((remote_peer != NULL), @@ -333,10 +408,9 @@ void handle_message(peer_t peer, msg_task_t task) XBT_DEBUG("Received a UNCHOKE message from %s (%s)", message->mailbox, message->issuer_host_name); remote_peer->choked_download = 0; - xbt_dict_set_ext(peer->active_peers, (char *) &message->peer_id, - sizeof(int), remote_peer, NULL); //Send requests to the peer, since it has unchoked us - send_requests_to_peer(peer, remote_peer); + if (remote_peer->am_interested) + request_new_piece_to_peer(peer, remote_peer); break; case MESSAGE_CHOKE: xbt_assert((remote_peer != NULL), @@ -344,29 +418,23 @@ void handle_message(peer_t peer, msg_task_t task) XBT_DEBUG("Received a CHOKE message from %s (%s)", message->mailbox, message->issuer_host_name); remote_peer->choked_download = 1; - xbt_ex_t e; - TRY { - xbt_dict_remove_ext(peer->active_peers, (char *) &message->peer_id, - sizeof(int)); - } - CATCH(e) { - xbt_ex_free(e); - } + remove_current_piece(peer, remote_peer, remote_peer->current_piece); break; case MESSAGE_HAVE: XBT_DEBUG("Received a HAVE message from %s (%s) of piece %d", message->mailbox, message->issuer_host_name, message->index); + xbt_assert(remote_peer->bitfield, "bitfield not received"); xbt_assert((message->index >= 0 && message->index < FILE_PIECES), "Wrong HAVE message received"); - if (remote_peer->bitfield == NULL) - return; remote_peer->bitfield[message->index] = '1'; peer->pieces_count[message->index]++; //If the piece is in our pieces, we tell the peer that we are interested. - if (!remote_peer->am_interested && in_current_pieces(peer, message->index)) { + if (!remote_peer->am_interested && peer->bitfield[message->index] == '0') { remote_peer->am_interested = 1; - send_interested(peer, remote_peer->mailbox); + send_interested(peer, message->mailbox); + if (!remote_peer->choked_download) + request_new_piece_to_peer(peer, remote_peer); } break; case MESSAGE_REQUEST: @@ -391,29 +459,19 @@ void handle_message(peer_t peer, msg_task_t task) && message->index < FILE_PIECES), "Wrong piece received"); //TODO: Execute à computation. if (message->stalled) { - XBT_DEBUG("The received piece %d from %s (%s) is STALLED", message->index, - message->mailbox, message->issuer_host_name); + XBT_DEBUG("The received piece %d from %s (%s) is STALLED", + message->index, message->mailbox, message->issuer_host_name); } else { XBT_DEBUG("Received piece %d (%d,%d) from %s (%s)", message->index, message->block_index, - message->block_index + message->block_length, message->mailbox, - message->issuer_host_name); + message->block_index + message->block_length, + message->mailbox, message->issuer_host_name); if (peer->bitfield[message->index] == '0') { update_bitfield_blocks(peer, message->index, message->block_index, message->block_length); if (piece_complete(peer, message->index)) { - peer->pieces_requested--; //Removing the piece from our piece list - unsigned i; - int piece_index = -1, piece; - xbt_dynar_foreach(peer->current_pieces, i, piece) { - if (piece == message->index) { - piece_index = i; - break; - } - } - xbt_assert(piece_index != -1, "Received an incorrect piece"); - xbt_dynar_remove_at(peer->current_pieces, piece_index, NULL); + remove_current_piece(peer, remote_peer, message->index); //Setting the fact that we have the piece peer->bitfield[message->index] = '1'; peer->pieces++; @@ -422,12 +480,19 @@ void handle_message(peer_t peer, msg_task_t task) send_have(peer, message->index); //sending UNINTERSTED to peers that doesn't have what we want. update_interested_after_receive(peer); + } else { // piece not completed + send_request_to_peer(peer, remote_peer, message->index); // ask for the next block } } else { XBT_DEBUG("However, we already have it"); + request_new_piece_to_peer(peer, remote_peer); } } break; + case MESSAGE_CANCEL: + XBT_DEBUG("The received CANCEL from %s (%s)", + message->mailbox, message->issuer_host_name); + break; } //Update the peer speed. if (remote_peer) { @@ -440,32 +505,28 @@ void handle_message(peer_t peer, msg_task_t task) task_message_free(task); } -/** - * Wait for the node to receive interesting bitfield messages (ie: non empty) - * to be received - * @param deadline peer deadline - * @param peer peer data - */ -void wait_for_pieces(peer_t peer, double deadline) +void request_new_piece_to_peer(peer_t peer, connection_t remote_peer) { - int finished = 0; - while (MSG_get_clock() < deadline && !finished) { - if (peer->comm_received == NULL) { - peer->task_received = NULL; - peer->comm_received = MSG_task_irecv(&peer->task_received, peer->mailbox); - } - msg_error_t status = MSG_comm_wait(peer->comm_received, TIMEOUT_MESSAGE); - //free the comm already, we don't need it anymore - MSG_comm_destroy(peer->comm_received); - peer->comm_received = NULL; - if (status == MSG_OK) { - MSG_task_get_data(peer->task_received); - handle_message(peer, peer->task_received); - if (peer->current_piece != -1) { - finished = 1; - } + int piece = select_piece_to_download(peer, remote_peer); + if (piece != -1) { + xbt_dynar_push_as(peer->current_pieces, int, piece); + send_request_to_peer(peer, remote_peer, piece); + } +} + +void remove_current_piece(peer_t peer, connection_t remote_peer, + int current_piece) +{ + int piece_index = -1, piece, i; + xbt_dynar_foreach(peer->current_pieces, i, piece) { + if (piece == current_piece) { + piece_index = i; + break; } } + if (piece_index != -1) + xbt_dynar_remove_at(peer->current_pieces, piece_index, NULL); + remote_peer->current_piece = -1; } /** @@ -483,53 +544,126 @@ void update_pieces_count_from_bitfield(peer_t peer, char *bitfield) } } + + /** - * Update the piece the peer is currently interested in. - * There is two cases (as described in "Bittorrent Architecture Protocol", Ryan Toole : - * If the peer has less than 3 pieces, he chooses a piece at random. + * Return the piece to be downloaded + * There are two cases (as described in "Bittorrent Architecture Protocol", Ryan Toole : + * If a piece is partially downloaded, this piece will be selected prioritarily + * If the peer has strictly less than 4 pieces, he chooses a piece at random. * If the peer has more than pieces, he downloads the pieces that are the less - * replicated + * replicated (rarest policy). + * If all pieces have been downloaded or requested, we select a random requested piece (endgame mode). + + * @param peer: local peer + * @param remote_peer: information about the connection + * @return the piece to download if possible. -1 otherwise */ -void update_current_piece(peer_t peer) +int select_piece_to_download(peer_t peer, connection_t remote_peer) { - if (xbt_dynar_length(peer->current_pieces) >= (FILE_PIECES - peer->pieces)) { - return; + int piece = -1; + + piece = partially_downloaded_piece(peer, remote_peer); + // strict priority policy + if (piece != -1) + return piece; + + // end game mode + if (xbt_dynar_length(peer->current_pieces) >= (FILE_PIECES - peer->pieces) + && is_interested(peer, remote_peer)) { + int i; + int nb_interesting_pieces = 0; + int random_piece_index, current_index = 0; + // compute the number of interesting pieces + for (i = 0; i < FILE_PIECES; i++) { + if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1') { + nb_interesting_pieces++; + } + } + xbt_assert(nb_interesting_pieces != 0, "WTF !!!"); + // get a random interesting piece + random_piece_index = + RngStream_RandInt(peer->stream, 0, nb_interesting_pieces - 1); + for (i = 0; i < FILE_PIECES; i++) { + if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1') { + if (random_piece_index == current_index) { + piece = i; + break; + } + current_index++; + } + } + xbt_assert(piece != -1, "WTF !!!"); + return piece; } - if (1 || peer->pieces < 3) { - int i = 0; - do { - peer->current_piece = - RngStream_RandInt(peer->stream, 0, FILE_PIECES - 1);; - i++; - } while (! - (peer->bitfield[peer->current_piece] == '0' - && !in_current_pieces(peer, peer->current_piece))); - } else { - //Trivial min algorithm. - int i, min_id = -1; - short min = -1; + // Random first policy + if (peer->pieces < 4 && is_interested_and_free(peer, remote_peer)) { + int i; + int nb_interesting_pieces = 0; + int random_piece_index, current_index = 0; + // compute the number of interesting pieces for (i = 0; i < FILE_PIECES; i++) { - if (peer->bitfield[i] == '0') { - min = peer->pieces_count[i]; - min_id = i; - break; + if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1' + && !in_current_pieces(peer, i)) { + nb_interesting_pieces++; } } - xbt_assert((min > -1), "Couldn't find a minimum"); - for (i = 1; i < FILE_PIECES; i++) { - if (peer->pieces_count[i] < min && peer->bitfield[i] == '0') { + xbt_assert(nb_interesting_pieces != 0, "WTF !!!"); + // get a random interesting piece + random_piece_index = + RngStream_RandInt(peer->stream, 0, nb_interesting_pieces - 1); + for (i = 0; i < FILE_PIECES; i++) { + if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1' + && !in_current_pieces(peer, i)) { + if (random_piece_index == current_index) { + piece = i; + break; + } + current_index++; + } + } + xbt_assert(piece != -1, "WTF !!!"); + return piece; + } else { // Rarest first policy + int i; + short min = SHRT_MAX; + int nb_min_pieces = 0; + int random_rarest_index, current_index = 0; + // compute the smallest number of copies of available pieces + for (i = 0; i < FILE_PIECES; i++) { + if (peer->pieces_count[i] < min && peer->bitfield[i] == '0' + && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i)) min = peer->pieces_count[i]; - min_id = i; + } + xbt_assert(min != SHRT_MAX + || !is_interested_and_free(peer, remote_peer), "WTF !!!"); + // compute the number of rarest pieces + for (i = 0; i < FILE_PIECES; i++) { + if (peer->pieces_count[i] == min && peer->bitfield[i] == '0' + && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i)) + nb_min_pieces++; + } + xbt_assert(nb_min_pieces != 0 + || !is_interested_and_free(peer, remote_peer), "WTF !!!"); + // get a random rarest piece + random_rarest_index = RngStream_RandInt(peer->stream, 0, nb_min_pieces - 1); + for (i = 0; i < FILE_PIECES; i++) { + if (peer->pieces_count[i] == min && peer->bitfield[i] == '0' + && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i)) { + if (random_rarest_index == current_index) { + piece = i; + break; + } + current_index++; } } - peer->current_piece = min_id; + xbt_assert(piece != -1 + || !is_interested_and_free(peer, remote_peer), "WTF !!!"); + return piece; } - xbt_dynar_push_as(peer->current_pieces, int, peer->current_piece); - XBT_DEBUG("New interested piece: %d", peer->current_piece); - xbt_assert((peer->current_piece >= 0 && peer->current_piece < FILE_PIECES), - "Peer want to retrieve a piece that doesn't exist."); } + /** * Update the list of current choked and unchoked peers, using the * choke algorithm @@ -537,34 +671,37 @@ void update_current_piece(peer_t peer) */ void update_choked_peers(peer_t peer) { + if (nb_interested_peers(peer) == 0) + return; + // if(xbt_dict_size(peer->active_peers) > 0) + // return; + XBT_DEBUG("(%d) update_choked peers %d active peers", peer->id, + xbt_dict_size(peer->active_peers)); //update the current round peer->round = (peer->round + 1) % 3; - char *key; + char *key, *key_choked; connection_t peer_choosed = NULL; + connection_t peer_choked = NULL; //remove a peer from the list xbt_dict_cursor_t cursor = NULL; xbt_dict_cursor_first(peer->active_peers, &cursor); if (xbt_dict_length(peer->active_peers) > 0) { - key = xbt_dict_cursor_get_key(cursor); - connection_t peer_choked = xbt_dict_cursor_get_data(cursor); - if (peer_choked) { - send_choked(peer, peer_choked->mailbox); - peer_choked->choked_upload = 1; - } - xbt_dict_remove_ext(peer->active_peers, key, sizeof(int)); + key_choked = xbt_dict_cursor_get_key(cursor); + peer_choked = xbt_dict_cursor_get_data(cursor); } xbt_dict_cursor_free(&cursor); - /** - * If we are currently seeding, we unchoke the peer which has - * been unchoke the least time. - */ + /** + * If we are currently seeding, we unchoke the peer which has + * been unchoke the least time. + */ if (peer->pieces == FILE_PIECES) { connection_t connection; double unchoke_time = MSG_get_clock() + 1; xbt_dict_foreach(peer->peers, cursor, key, connection) { - if (connection->last_unchoke < unchoke_time && connection->interested) { + if (connection->last_unchoke < unchoke_time && connection->interested + && connection->choked_upload) { unchoke_time = connection->last_unchoke; peer_choosed = connection; } @@ -575,9 +712,8 @@ void update_choked_peers(peer_t peer) int j = 0; do { //We choose a random peer to unchoke. - int id_chosen = - RngStream_RandInt(peer->stream, 0, - xbt_dict_length(peer->peers) - 1); + int id_chosen = RngStream_RandInt(peer->stream, 0, + xbt_dict_length(peer->peers) - 1); int i = 0; connection_t connection; xbt_dict_foreach(peer->peers, cursor, key, connection) { @@ -588,7 +724,7 @@ void update_choked_peers(peer_t peer) i++; } xbt_dict_cursor_free(&cursor); - if (peer_choosed->interested == 0) { + if (!peer_choosed->interested || !peer_choosed->choked_upload) { peer_choosed = NULL; } j++; @@ -598,8 +734,8 @@ void update_choked_peers(peer_t peer) connection_t connection; double fastest_speed = 0.0; xbt_dict_foreach(peer->peers, cursor, key, connection) { - if (connection->peer_speed > fastest_speed && connection->choked_upload - && connection->interested) { + if (connection->peer_speed > fastest_speed + && connection->choked_upload && connection->interested) { peer_choosed = connection; fastest_speed = connection->peer_speed; } @@ -607,14 +743,45 @@ void update_choked_peers(peer_t peer) } } - if (peer_choosed != NULL) { - peer_choosed->choked_upload = 0; - xbt_dict_set_ext(peer->active_peers, (char *) &peer_choosed->id, - sizeof(int), peer_choosed, NULL); - peer_choosed->last_unchoke = MSG_get_clock(); - send_unchoked(peer, peer_choosed->mailbox); - } + if (peer_choosed != NULL) + XBT_DEBUG + ("(%d) update_choked peers unchoked (%d) ; int (%d) ; choked (%d) ", + peer->id, peer_choosed->id, peer_choosed->interested, + peer_choosed->choked_upload); + + // if (xbt_dict_size(peer->peers) > 0) + // xbt_assert((xbt_dict_size(peer->active_peers) != 0), + // "No more active peers !"); + + // if (peer_choked != NULL && peer_choked->choked_upload != 0) + // peer_choked = NULL; + // if (peer_choosed != NULL && peer_choosed->choked_upload == 0) + // peer_choosed = NULL; + + if (peer_choked != peer_choosed) { + if (peer_choked != NULL) { + xbt_assert((!peer_choked->choked_upload), + "Tries to choked a choked peer"); + peer_choked->choked_upload = 1; + xbt_assert((*((int *) key_choked) == peer_choked->id), "WTF !!!"); + update_active_peers_set(peer, peer_choked); + // xbt_dict_remove_ext(peer->active_peers, key_choked, sizeof(int)); + XBT_DEBUG("(%d) Sending a CHOKE to %d", peer->id, peer_choked->id); + send_choked(peer, peer_choked->mailbox); + } + if (peer_choosed != NULL) { + xbt_assert((peer_choosed->choked_upload), + "Tries to unchoked an unchoked peer"); + peer_choosed->choked_upload = 0; + xbt_dict_set_ext(peer->active_peers, (char *) &peer_choosed->id, + sizeof(int), peer_choosed, NULL); + peer_choosed->last_unchoke = MSG_get_clock(); + XBT_DEBUG("(%d) Sending a UNCHOKE to %d", peer->id, peer_choosed->id); + update_active_peers_set(peer, peer_choosed); + send_unchoked(peer, peer_choosed->mailbox); + } + } } /** @@ -632,15 +799,16 @@ void update_interested_after_receive(peer_t peer) xbt_dict_foreach(peer->peers, cursor, key, connection) { interested = 0; if (connection->am_interested) { + xbt_assert(connection->bitfield, "Bitfield not received"); //Check if the peer still has a piece we want. - xbt_dynar_foreach(peer->current_pieces, cpt, piece) { - xbt_assert((piece >= 0), "Wrong piece."); - if (connection->bitfield && connection->bitfield[piece] == '1') { + int i; + for (i = 0; i < FILE_PIECES; i++) { + if (connection->bitfield[i] == '1' && peer->bitfield[i] == '0') { interested = 1; break; } } - if (!interested) { + if (!interested) { //no more piece to download from connection connection->am_interested = 0; send_notinterested(peer, connection->mailbox); } @@ -676,7 +844,8 @@ int piece_complete(peer_t peer, int index) } /** - * Returns the first block that a peer doesn't have in a piece + * Returns the first block that a peer doesn't have in a piece. + * If the peer has all blocks of the piece, returns -1. */ int get_first_block(peer_t peer, int piece) { @@ -689,55 +858,104 @@ int get_first_block(peer_t peer, int piece) return -1; } +/** + * Indicates if the remote peer has a piece not stored by the local peer + */ +int is_interested(peer_t peer, connection_t remote_peer) +{ + xbt_assert(remote_peer->bitfield, "Bitfield not received"); + int i; + for (i = 0; i < FILE_PIECES; i++) { + if (remote_peer->bitfield[i] == '1' && peer->bitfield[i] == '0') { + return 1; + } + } + return 0; +} + +/** + * Indicates if the remote peer has a piece not stored by the local peer nor requested by the local peer + */ +int is_interested_and_free(peer_t peer, connection_t remote_peer) +{ + xbt_assert(remote_peer->bitfield, "Bitfield not received"); + int i; + for (i = 0; i < FILE_PIECES; i++) { + if (remote_peer->bitfield[i] == '1' && peer->bitfield[i] == '0' + && !in_current_pieces(peer, i)) { + return 1; + } + } + return 0; +} + + +/** + * Returns a piece that is partially downloaded and stored by the remote peer if any + * -1 otherwise. + */ +int partially_downloaded_piece(peer_t peer, connection_t remote_peer) +{ + xbt_assert(remote_peer->bitfield, "Bitfield not received"); + int i; + for (i = 0; i < FILE_PIECES; i++) { + if (remote_peer->bitfield[i] == '1' && peer->bitfield[i] == '0' + && !in_current_pieces(peer, i)) { + if (get_first_block(peer, i) > 0) + return i; + } + } + return -1; +} + + /** * Send request messages to a peer that have unchoked us * @param peer peer * @param remote_peer peer data to the peer we want to send the request */ -void send_requests_to_peer(peer_t peer, connection_t remote_peer) +void send_request_to_peer(peer_t peer, connection_t remote_peer, int piece) { + remote_peer->current_piece = piece; unsigned i; - int piece, block_index, block_length; - xbt_dynar_foreach(peer->current_pieces, i, piece) { - if (remote_peer->bitfield && remote_peer->bitfield[piece] == '1') { - block_index = get_first_block(peer, piece); - if (block_index != -1) { - block_length = PIECES_BLOCKS - block_index; - block_length = min(BLOCKS_REQUESTED, block_length); - send_request(peer, remote_peer->mailbox, piece, block_index, - block_length); - break; - } - } + int block_index, block_length; + xbt_assert(remote_peer->bitfield, "bitfield not received"); + xbt_assert(remote_peer->bitfield[piece] == '1', "WTF !!!"); + block_index = get_first_block(peer, piece); + if (block_index != -1) { + block_length = PIECES_BLOCKS - block_index; + block_length = min(BLOCKS_REQUESTED, block_length); + send_request(peer, remote_peer->mailbox, piece, block_index, block_length); } } + /** - * Find the peers that have the current interested piece and send them - * the "interested" message + * Indicates if a piece is currently being downloaded by the peer. */ -void send_interested_to_peers(peer_t peer) +int in_current_pieces(peer_t peer, int piece) { - char *key; - xbt_dict_cursor_t cursor = NULL; - connection_t connection; - xbt_assert((peer->current_piece != -1), - "Tried to send a interested message wheras the current_piece is -1"); - xbt_dict_foreach(peer->peers, cursor, key, connection) { - if (connection->bitfield - && connection->bitfield[peer->current_piece] == '1') { - connection->am_interested = 1; - msg_task_t task = - task_message_new(MESSAGE_INTERESTED, peer->hostname, peer->mailbox, - peer->id, task_message_size(MESSAGE_INTERESTED)); - MSG_task_dsend(task, connection->mailbox, task_message_free); - XBT_DEBUG("Send INTERESTED to %s", connection->mailbox); + unsigned i; + int peer_piece; + xbt_dynar_foreach(peer->current_pieces, i, peer_piece) { + if (peer_piece == piece) { + return 1; } } - peer->current_piece = -1; - peer->pieces_requested++; + return 0; } + + + +/*********************************************************** + * + * Low level message functions + * + ***********************************************************/ + + + /** * Send a "interested" message to a peer * @param peer peer data @@ -807,7 +1025,7 @@ void send_choked(peer_t peer, const char *mailbox) { XBT_DEBUG("Sending a CHOKE to %s", mailbox); msg_task_t task = - task_message_new(MESSAGE_CHOKE, peer->hostname, peer->mailbox, + task_message_new(MESSAGE_CHOKE, peer->hostname, peer->mailbox, peer->id, task_message_size(MESSAGE_CHOKE)); MSG_task_dsend(task, mailbox, task_message_free); } @@ -836,7 +1054,8 @@ void send_have(peer_t peer, int piece) xbt_dict_foreach(peer->peers, cursor, key, remote_peer) { msg_task_t task = task_message_index_new(MESSAGE_HAVE, peer->hostname, peer->mailbox, - peer->id, piece, task_message_size(MESSAGE_HAVE)); + peer->id, piece, + task_message_size(MESSAGE_HAVE)); MSG_task_dsend(task, remote_peer->mailbox, task_message_free); } } @@ -851,14 +1070,16 @@ void send_bitfield(peer_t peer, const char *mailbox) msg_task_t task = task_message_bitfield_new(peer->hostname, peer->mailbox, peer->id, peer->bitfield, FILE_PIECES); - MSG_task_dsend(task, mailbox, task_message_free); + //Async send and append to pending sends + msg_comm_t comm = MSG_task_isend(task, mailbox); + xbt_dynar_push(peer->pending_sends, &comm); } /** * Send a "request" message to a pair, containing a request for a piece */ -void send_request(peer_t peer, const char *mailbox, int piece, int block_index, - int block_length) +void send_request(peer_t peer, const char *mailbox, int piece, + int block_index, int block_length) { XBT_DEBUG("Sending a REQUEST to %s for piece %d (%d,%d)", mailbox, piece, block_index, block_length); @@ -884,16 +1105,3 @@ void send_piece(peer_t peer, const char *mailbox, int piece, int stalled, stalled, block_index, block_length, BLOCK_SIZE); MSG_task_dsend(task, mailbox, task_message_free); } - -int in_current_pieces(peer_t peer, int piece) -{ - unsigned i; - int is_in = 0, peer_piece; - xbt_dynar_foreach(peer->current_pieces, i, peer_piece) { - if (peer_piece == piece) { - is_in = 1; - break; - } - } - return is_in; -}